Preheating process

- Feb 07, 2019-

The main purpose of preheating in selective welding process is not to reduce thermal stress, but to remove solvent pre-drying flux, so that the flux has the correct viscosity before entering the welding sipo. When welding, the effect of preheating heat on welding quality is not a key factor, PCB material thickness, device packaging specifications and flux type determine the setting of preheating temperature. In selective welding, there are different theoretical explanations for preheating: Some process engineers believe that the PCB should be preheated before the flux is sprayed, and the other view is that there is no need for preheating to weld directly. Users can arrange the process of selective welding according to the specific situation.